Walkie talkie to sip phone interface

I’ve been trying to find a solution that would allow our sip phones to
communication with walkie talkies. Our setup is that we have sip phones
setup in 2 locations, headquarters and dome. We can communication from
headquarters and dome through sip phones, but within the dome we have
technicians that use walkie talkies to communicate as they go about
their work. Our hope is to allow 2 way communications from our sip
phones at headquarters (or within the dome) with our technicians using
their walkie talkies as they are working throughout the dome. Not sure
if this is possible but I would appreciate any suggestions.